Table 3.

IRRs for Alzheimer's dementia in individuals with an offspring with schizophrenia, other psychiatric service contact, bipolar disorder, other affective disorder or personality disorder compared to individuals with an offspring without psychiatric service contact

Offspring's mental history	Casesa	IRR (95% CI)b
Only individuals with mental disorders
Schizophrenia	103	0.71 (0.58–0.86)
Bipolar disorder	7c	0.72 (0.31–1.40)
Other affective disorder	70	1.05 (0.82–1.32)
Personality disorder	40	0.80 (0.57–1.07)
Other psychiatric contact	293	0.82 (0.72–0.93)
No psychiatric contact	1,628	1.00 (reference)
Only individuals with no mental disorders
Schizophrenia	314	1.09 (0.97–1.21)
Bipolar disorder	22	1.10 (0.70–1.63)
Other affective disorder	174	1.07 (0.92–1.24)
Personality disorder	127	1.19 (1.00–1.42)
Other psychiatric contact	1,132	1.12 (1.05–1.19)
No psychiatric contact	8,580	1.00 (reference)

^aNumber of individuals with Alzheimer's dementia.

^bAdjusted for calendar year, birth place, sex and its interaction with age.

^cShould be interpreted with caution because of the few exposed cases.